Fiber Bundle Supply Device

ABSTRACT

This fiber bundle supply device ( 32 ) is provided with: plural bobbin holder shafts each of which supports a bobbin (B) around which a fiber bundle (F) is wound; and a turntable ( 323 ) on which the bobbin holder shafts are arranged in a concentric pattern and which rotates around the central axis (C) of said concentric circle, wherein the bobbin holder shafts are configured from at least a first bobbin holder shaft ( 321 ) which supports a first bobbin (B 1 ), and a second bobbin holder shaft ( 322 ) which supports a second bobbin (B 2 ). If the fiber bundle (F) wound around the first bobbin (B 1 ) has been unwound and little remains, by rotating the turntable ( 323 ) and splicing the fiber bundle (F) of the first bobbin (B 1 ) and the fiber bundle (F) of the second bobbin (B 2 ), unwinding of the fiber bundle (F) wound around the second bobbin (B 2 ) is started.

TECHNICAL FIELD

The present invention relates to a technique of a fiber bundle supplydevice.

BACKGROUND ART

Conventionally, a filament winding device which winds fiber bundlesaround the outer periphery surface of a liner has been known. Thefilament winding device is provided with a fiber bundle supply part, anda plurality of bobbins around which the fiber bundle is wound arearranged in the fiber bundle supply part (for example, see PatentLiterature 1). With regard to the filament winding device, the fiberbundle is unwound from each bobbin arranged in the fiber bundle supplypart, and the fiber bundles are wound around the outer periphery surfaceof the liner.

However, with regard to the conventional filament winding device, whenone bobbin arranged in the fiber bundle supply part becomes an emptybobbin, there is a need to stop the fiber bundle winding operation andchange the bobbin. Accordingly, there is a problem that the fiber bundlewinding operation is interrupted frequently, and thus productivity isreduced.

PRIOR ART DOCUMENTS Patent Literature

Patent Literature 1: the Japanese Patent Laid Open Gazette 2010-23481

SUMMARY OF THE INVENTION Problems to Be Solved by the Invention

The present invention is made in order to solve the above-describedproblems. An object of the present invention is to provide a techniquein which if a fiber bundle wound around one bobbin has been unwound andlittle remains, unwinding of a fiber bundle wound around the otherbobbin is started, whereby the fiber bundle is continuously supplied.

Means for Solving the Problems

A first aspect of the present invention is a fiber bundle supply deviceincluding: plural bobbin holder shafts each of which supports a bobbinaround which a fiber bundle is wound; and a turntable on which thebobbin holder shafts are arranged in a concentric pattern and whichrotates around the central axis of the concentric circle. The bobbinholder shafts are configured from at least a first bobbin holder shaftwhich supports a first bobbin, and a second bobbin holder shaft whichsupports a second bobbin. If the fiber bundle wound around the firstbobbin has been unwound and little remains, by rotating the turntableand splicing the fiber bundle of the first bobbin and the fiber bundleof the second bobbin, unwinding of the fiber bundle wound around thesecond bobbin is started.

A second aspect of the present invention is the fiber bundle supplydevice according to the first aspect which includes a first fiber bundleguide and a second fiber bundle guide which are installed on theturntable and which rotate with the turntable. When the turntable startsrotation, the first fiber bundle guide guides the fiber bundle unwoundfrom the first bobbin to be restricted in a prescribed trajectory. Andwhen the rotation of the turntable is terminated, the second fiberbundle guide superposes the end portion of the fiber bundle wound aroundthe second bobbin on the fiber bundle unwound from the first bobbin.

A third aspect of the present invention is the fiber bundle supplydevice according to the first or the second aspect which includes asplicing device which splices the fiber bundle of the first bobbin andthe fiber bundle of the second bobbin together. The splicing devicesplices the overlapped portion of the fiber bundle of the first bobbinand the fiber bundle of the second bobbin.

A fourth aspect of the present invention is the fiber bundle supplydevice according to any one of the first to the third aspect whichincludes a cutter device which cuts the fiber bundle unwound from thefirst bobbin. The cutter device cuts the fiber bundle unwound from thefirst bobbin such that necessary and sufficient bonding strength isobtained when all of the overlapped portion of the fiber bundle isspliced.

Effects of the Invention

The present invention exerts effects described below.

According to the first aspect, if the fiber bundle wound around a firstbobbin has been unwound and little remains, unwinding of the fiberbundle wound around a second bobbin is started, whereby the fiber bundleis continuously supplied. As such, the fiber bundle can be continuouslysupplied.

According to the second aspect, the end portion of the fiber bundlewound around the second bobbin can be overlapped with the fiber bundleunwound from the first bobbin and restricted in the prescribedtrajectory. As such, the fiber bundle of the first bobbin can be splicedwith the fiber bundle of the second bobbin.

According to the third aspect, the overlapped portion of the fiberbundle of the first bobbin and the fiber bundle of the second bobbin canbe spliced. As such, the fiber bundle of the first bobbin can be surelyspliced with the fiber bundle of the second bobbin.

According to the fourth aspect, necessary and sufficient bondingstrength can be obtained with respect to the splicing portion of thefiber bundle of the first bobbin and the fiber bundle of the secondbobbin. As such, required bonding strength can be secured for thesplicing portion, and time required for splicing can be shortened.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an overall configuration of a filament winding device100.

FIG. 2 illustrates a configuration of a fiber bundle supply device 32.

FIG. 3 illustrates a state in which a fiber bundle F wound around afirst bobbin B1 is unwound.

FIG. 4 illustrates a state in which rotation of a turntable 323 isstarted.

FIG. 5 illustrates a state in which rotation of the turntable 323 isterminated.

FIG. 6 illustrates a state in which an overlapped portion of the fiberbundle F is spliced by a splicing device 326.

FIG. 7 illustrates a state in which the fiber bundle F unwound from thefirst bobbin B1 is cut by a cutter device 327.

FIG. 8 illustrates a state in which rotation of the turntable 323 to thereverse direction is terminated.

FIG. 9 illustrates a state in which the fiber bundle F wound around asecond bobbin B2 is unwound.

FIG. 10 illustrates a state in which a new bobbin B is fitted to a firstbobbin holder shaft 321.

FIG. 11 illustrates a state in which the fiber bundle F is restricted ina prescribed trajectory.

FIG. 12 illustrates a state in which the fiber bundle F of the firstbobbin B1 is superposed on the fiber bundle F of the second bobbin B2.

DESCRIPTION OF NOTATIONS

-   1 liner-   10 liner transfer part-   11 pedestal-   12 liner support frame-   13 rotational shaft-   20 helical winding part-   21 pedestal-   22 helical head-   23 guide-   30 fiber bundle supply part-   31 rack-   32 fiber bundle supply device-   321 first bobbin holder shaft-   322 second bobbin holder shaft-   323 turntable-   324 first fiber bundle guide-   325 second fiber bundle guide-   B bobbin-   B1 first bobbin-   B2 second bobbin-   C central axis-   F fiber bundle-   P1 unwinding position-   P2 standby position

DESCRIPTION OF EMBODIMENTS

Next, an explanation will be given of embodiments of the presentinvention.

A fiber bundle supply device 32 according to the embodiment of thepresent invention is included in a fiber bundle supply part 30 whichconfigures a filament winding device 100. Therefore, first of all, abrief explanation will be given of an overall configuration of thefilament winding device 100 (hereinafter referred to as “FW device100”).

FIG. 1 illustrates the overall configuration of the FW device 100. Anarrow D in the drawing indicates a transfer direction of a liner 1. Thedirection in parallel to the transfer direction of the liner 1 isregarded as the longitudinal direction of the FW device 100, and onedirection of transferring the liner 1 and other direction oppositethereto are respectively defined as the front side and the rear side.The FW device 100 reciprocates the liner 1 in the longitudinaldirection, whereby the front side and the rear side is defined dependingon the transfer direction of the liner 1.

The FW device 100 winds a fiber bundle F around the outer peripherysurface of the liner 1. The FW device 100 mainly includes a linertransfer part 10, a helical winding part 20, and the fiber bundle supplypart 30.

The liner transfer part 10 transfers the liner 1 while rotating it. Inparticular, the liner 1 is rotated about the longitudinal direction ofthe FW device 100 as a center axis, and is transferred in thelongitudinal direction of the FW device 100 by the liner transfer part10. The liner transfer part 10 mainly includes a pedestal 11, linersupport frames 12, and a rotational shaft 13.

The pedestal 11 is placed on a pair of rails extending in thelongitudinal direction of the FW device 100. The pedestal 11 is providedwith the pair of liner support frames 12 and the rotational shaft 13.The liner 1 is attached to the rotational shaft 13 and is rotated in onedirection via a power mechanism (not shown).

Because of this configuration, it is possible that the liner 1 isrotated about the longitudinal direction of the FW device 100 as acenter axis, and is transferred in the longitudinal direction of the FWdevice 100 by the liner transfer part 10.

The helical winding part 20 winds the fiber bundles F around the outerperiphery surface of the liner 1. In particular, the helical windingpart 20 performs so-called helical winding in which the winding angle ofthe fiber bundle F is set to be a prescribed value relative to thelongitudinal direction of the FW device 100. The helical winding part 20mainly includes a pedestal 21 and a helical head 22.

The pedestal 21 is provided with the helical head 22. The helical head22 is provided with a plurality of guides 23 each of which guides thefiber bundle F. The fiber bundle F guided by each guide 23 is woundaround the outer periphery surface of the liner 1 passing through whilerotating.

Because of this configuration, it is possible that the helical windingpart 20 performs so-called helical winding, where the winding angle ofthe fiber bundle F is set to be the prescribed value relative to thelongitudinal direction of the FW device 100.

The fiber bundle supply part 30 supplies the fiber bundles F to thehelical winding part. In particular, the fiber bundle supply part 30supplies the fiber bundle F to each guide 23 of the helical head 22included in the helical winding part 20. The fiber bundle supply part 30mainly includes a rack 31 and the fiber bundle supply devices 32.

The rack 31 is provided with the plurality of fiber bundle supplydevices 32. The fiber bundle supply device 32 supports bobbins B aroundwhich the fiber bundle F is wound. And the fiber bundle F wound aroundeach bobbin B is supplied to corresponding respective guide 23 through aguide member (not shown).

Because of this configuration, it is possible that the fiber bundle F isfed to each guide 23 of the helical head 22 included in the helicalwinding part 20 by the fiber bundle supply part 30.

Next, a detailed explanation will be given of the configuration of thefiber bundle supply device 32.

FIG. 2 illustrates the configuration of the fiber bundle supply device32. Here, explanation will be given by using the case of a two-shafttype fiber bundle supply device which has two bobbin holder shafts 321,322 each of which supports the bobbin B. However, even in the case of athree-shaft type fiber bundle supply device or a four-shaft type fiberbundle supply device, the same object and effects according to thepresent invention can be achieved. The scope of the present inventionalso encompasses such a modification.

If the fiber bundle F wound around one bobbin B has been unwound andlittle remains, the fiber bundle supply device 32 starts unwinding ofthe fiber bundle F wound around the other bobbin B, whereby the fiberbundle F is continuously supplied. The fiber bundle supply device 32mainly includes the first bobbin holder shaft 321, the second bobbinholder shaft 322, a turntable 323, a first fiber bundle guide 324, and asecond fiber bundle guide 325. Here, the bobbin B supported by the firstbobbin holder shaft 321 is defined as the first bobbin B1, whereas thebobbin B supported by the second bobbin holder shaft 322 is defined asthe second bobbin B2.

The first bobbin holder shaft 321 rotatably supports the first bobbinB1. When the fiber bundle F is pulled, the first bobbin B1 rotates,whereby the fiber bundle F is unwound. When the first bobbin holdershaft 321 is at an unwinding position P1, the fiber bundle F woundaround the first bobbin B1 is unwound (see the black arrows in FIG. 3).And, as explained above, the fiber bundle F unwound from the firstbobbin B1 is supplied to corresponding guide 23 of the helical head 22.

The second bobbin holder shaft 322 rotatably supports the second bobbinB2. When the fiber bundle F is pulled, the second bobbin B2 rotates,whereby the fiber bundle F is unwound. When the second bobbin holdershaft 322 is at the unwinding position P1, the fiber bundle F woundaround the second bobbin B2 is unwound (see the black arrows in FIG. 9).And, as explained above, the fiber bundle F unwound from the secondbobbin B2 is supplied to corresponding guide 23 of the helical head 22.

The defined discrimination between the first bobbin holder shaft 321 andthe second bobbin holder shaft 322 is made for the purpose ofillustration, and these shafts each have the same configuration.

The first bobbin holder shaft 321 and the second bobbin holder shaft 322are arranged on a concentric circle on the turntable 323, and theturntable 323 rotates around the central axis C of the concentriccircle. When the turntable 323 is rotated around the central axis Cnearly by 180°, the position of the first bobbin holder shaft 321 at theunwinding position P1 and the position of the second bobbin holder shaft322 at a standby position P2 are switched with each other (see FIG. 5).When the second bobbin holder shaft 322 is at the unwinding position P1and the first bobbin holder shaft 321 is at the standby position P2, theposition of the second bobbin holder shaft 322 at the unwinding positionP1 and the position of the first bobbin holder shaft 321 at the standbyposition P2 are switched with each other.

The first fiber bundle guide 324 is installed on the turntable 323 andis rotated with the turntable 323. When the turntable 323 startsrotation, the first fiber bundle guide 324 guides the fiber bundle Funwound from the first bobbin B1 to be restricted in a prescribedtrajectory (see FIG. 4, FIG. 11). When the first bobbin holder shaft 321is at the standby position P2 and the first bobbin holder shaft 321 isswitched with the second bobbin holder shaft 322 which is at theunwinding position P1, the end portion of the fiber bundle F woundaround the first bobbin B1 is superposed on the fiber bundle F unwoundfrom the second bobbin B2. Specific configuration will be explainedlater.

The second fiber bundle guide 325 is installed on the turntable 323 andis rotated with the turntable 323. When the rotation of the turntable323 is terminated, the second fiber bundle guide 325 superposes the endportion of the fiber bundle F wound around the second bobbin B2 on thefiber bundle F unwound from the first bobbin B1 (see FIG. 5, FIG. 12).When the second bobbin holder shaft 322 is at the unwinding position P1and the second bobbin holder shaft 322 is switched with the first bobbinholder shaft 321 which is at the standby position P2, the fiber bundle Funwound from the second bobbin B2 is guided to be restricted in theprescribed trajectory. Specific configuration will be explained later.

The defined discrimination between the first fiber bundle guide 324 andthe second fiber bundle guide 325 is made for the purpose ofillustration, and these guides each have the same configuration.

Next, explanation will be given of an operation mode of the fiber bundlesupply device 32 at the time of changing a bobbin.

FIG. 3 to FIG. 10 illustrate an example of operation of the fiber bundlesupply device 32 at the time of changing a bobbin. The black arrows inthe drawings indicate the rotation direction of the first bobbin B1 andthe second bobbin B2 and the sending-out direction of the fiber bundleF. The white arrows in the drawings indicate the rotation direction ofthe turntable 323. Here, explanation will be given by assuming the casein which the first bobbin holder shaft 321 is at the unwinding positionP1 and the second bobbin holder shaft 322 is at the standby position P2.

FIG. 3 illustrates a state in which the fiber bundle F wound around thefirst bobbin B1 is unwound. As shown in FIG. 3, when the fiber bundle Fis pulled, the first bobbin B1 rotates, whereby the fiber bundle F isunwound. Since the fiber bundle F is momentarily unwound from the firstbobbin B1, the remaining amount of the fiber bundle F wound around thefirst bobbin B1 gradually decreases. Therefore, the first bobbin B1 hasto be changed to the second bobbin B2 before all of the fiber bundle Fwound around the first bobbin B1 is unwound and the first bobbin B1becomes an empty bobbin.

FIG. 4 illustrates a state in which the turntable 323 starts rotation.As shown in FIG. 4, when the turntable 323 starts rotation, the firstfiber bundle guide 324 pushes up the fiber bundle F unwound from thefirst bobbin B1. At this time, the first fiber bundle guide 324 guidesthe fiber bundle F unwound from the first bobbin B1 to be restricted inthe prescribed trajectory.

Specifically, as shown in FIG. 11, the first fiber bundle guide 324includes a pair of guide walls 324 a which gradually become narrow alongthe feeding direction of the fiber bundle F. When the fiber bundle F ispushed up, the guide walls 324 a lead the fiber bundle F to a bottomwall 324 b. Then, the fiber bundle F unwound from the first bobbin B1 isguided by the guide walls 324 a and the bottom wall 324 b and sent outfrom a fiber bundle passage 324 c which is arranged at an end portion.Thus, the first fiber bundle guide 324 guides the fiber bundle Ftraversed (see “T” in the drawing) in the shaft direction of the firstbobbin B1 to be restricted in the prescribed trajectory.

FIG. 5 illustrates a state in which the rotation of the turntable 323 isterminated. As shown in FIG. 5, when the rotation of the turntable 323is terminated, the second fiber bundle guide 325 comes in contact withthe fiber bundle F unwound from the first bobbin B1. At this time, thesecond fiber bundle guide 325 superposes the end portion of the fiberbundle F wound around the second bobbin B2 on the fiber bundle F unwoundfrom the first bobbin B1.

Specifically, as shown in FIG. 12, the second fiber bundle guide 325includes a holder 325 d which holds the tip end portion of the fiberbundle F. The holder 325 d retains the fiber bundle F wound around thesecond bobbin B2 in such a state to run along a bottom wall 325 b. Then,by rotating the turntable 323, the fiber bundle F wound around thesecond bobbin B2 is guided in such a state to run along the fiber bundleF unwound from the first bobbin B1. As such, the second fiber bundleguide 325 superposes the end portion of the fiber bundle F wound aroundthe second bobbin B2 on the fiber bundle F unwound from the first bobbin1.

Because of this configuration, it is possible that the end portion ofthe fiber bundle F wound around the second bobbin B2 is overlapped withthe fiber bundle F unwound from the first bobbin B1 and restricted inthe prescribed trajectory by the present fiber bundle supply device 32.As such, the fiber bundle F of the first bobbin B1 can be spliced withthe fiber bundle F of the second bobbin B2.

FIG. 6 illustrates a state where the overlapped portion of the fiberbundle F is spliced by a splicing device 326. As shown in FIG. 6, withrespect to the splicing device 326, the overlapped portion of the fiberbundle F is nipped and held by the splicing device 326 and the secondfiber bundle guide 325. And the splicing device 326 applies heat to theoverlapped portion of the fiber bundles F, whereby these fiber bundles Fare spliced.

Specifically, the splicing device 326 includes a heater part 326 a whichbecomes hot due to a flow of current. The heater part 326 a applies heatto the overlapped portion of the fiber bundles F, whereby each of thefiber bundles F are thermally-cured and spliced. As such, the fiberbundle F of the first bobbin B1 can be surely spliced with the fiberbundle F of the second bobbin B2 by the splicing device 326 with asimple configuration.

As another component, the overlapped portion of the fiber bundles F maybe depressed and spliced by the splicing device 326. Moreover, theoverlapped portion of the fiber bundles F may be stitched up and splicedby the splicing device 326. As such, the fiber bundle F of the firstbobbin B1 can be surely spliced with the fiber bundle F of the secondbobbin B2 by the splicing device 326 with a simple configuration. Also,each of the fiber bundles F may be spliced by using other methods suchas confounding etc.

Because of this configuration, it is possible that the overlappedportion of the fiber bundle F of the first bobbin B1 and the fiberbundle F of the second bobbin B2 is spliced by the fiber bundle supplydevice 32. Accordingly, the fiber bundle F of the first bobbin B1 can besurely spliced with the fiber bundle F of the second bobbin B2.

Furthermore, the fiber bundle supply device 32 sends out the fiberbundle F while splicing the fiber bundle F of the first bobbin B1 andthe fiber bundle F of the second bobbin B2. This makes it possible toeasily change the length of the splicing portion and the splicingpattern. As such, it is also possible to secure the flexibility of thesplicing portion by intermittently splicing the overlapped portion ofthe fiber bundle F.

FIG. 7 illustrates a state where the fiber bundle F unwound from thefirst bobbin B1 is cut by a cutter device 327. As shown in FIG. 7, thecutter device 327 divides the fiber bundle F unwound from the firstbobbin B1 between the first bobbin B1 and the second bobbin B2.

Specifically, the cutter device 327 includes a cutter 327 a which cutsthe fiber bundle F. The fiber bundle F unwound from the first bobbin B1spanned between the first bobbin B1 and the second bobbin B2 is dividedby the cutter 327 a. The time that the fiber bundle F is cut isdetermined based on the bonding strength required for the splicingportion. That is to say, the fiber bundle F is cut by the cutter device327 such that the fiber bundle F would not separate even when thetensile load is applied to the fiber bundle F when all of the overlappedportion of the fiber bundle F is spliced, and prevent the length of thesplicing portion from being elongated more than necessary.

Because of this configuration, it is possible that necessary andsufficient bonding strength is secured with respect to the splicingportion of the fiber bundle F of the first bobbin B1 and the fiberbundle F of the second bobbin B2 by the fiber bundle supply device 32.Accordingly, required bonding strength can be secured for the splicingportion, and time required for splicing can be shortened.

FIG. 8 illustrates a state where rotation of the turntable 323 to thereverse direction is terminated. As shown in FIG. 8, the second fiberbundle guide 325 is rotated to the reverse direction with the turntable323, whereby the second fiber bundle guide 325 is separated from thefiber bundle F of the second bobbin B2.

FIG. 9 illustrates a state where the fiber bundle F wound around thesecond bobbin B2 is unwound. As shown in FIG. 9, when the fiber bundle Fis pulled, the second bobbin B2 rotates, whereby the fiber bundle F isunwound. Since the fiber bundle F is momentarily unwound from the secondbobbin B2, the remaining amount of the fiber bundle F wound around thesecond bobbin B2 gradually decreases. Therefore, the second bobbin B2has to be changed to the first bobbin B1 by fitting a new bobbin B(first bobbin B1) to the first bobbin holder shaft 321 before all of thefiber bundle F wound around the second bobbin B2 is unwound and thesecond bobbin B2 becomes an empty bobbin.

FIG. 10 illustrates a state where a new bobbin B (first bobbin B1) isfitted to the first bobbin holder shaft 321. As shown in FIG. 10, byfitting the new bobbin B (first bobbin B1) to the first bobbin holdershaft 321, the bobbin B (first bobbin B1) can be kept at a standby. Assuch, if the fiber bundle F wound around the second bobbin B2 has beenunwound and little remains, unwinding of the fiber bundle F wound aroundthe new bobbin B (first bobbin B1) is started, whereby the fiber bundleF is continuously supplied.

As described above, with respect to the fiber bundle supply device 32according to the embodiment of the present invention, if the fiberbundle F wound around the first bobbin B1 has been unwound and littleremains, unwinding of the fiber bundle F wound around the second bobbinB2 is started, whereby the fiber bundle F is continuously supplied. Andif the fiber bundle F wound around the second bobbin B2 has been unwoundand little remains, unwinding of the fiber bundle F wound around thefirst bobbin B1 is started, whereby the fiber bundle F is continuouslysupplied. As such, the fiber bundle F can be continuously supplied.

INDUSTRIAL APPLICABILITY

The present invention can be utilized to a technique of a fiber bundlesupply device.

1. A fiber bundle supply device comprising: plural bobbin holder shaftseach of which supports a bobbin around which a fiber bundle is wound;and a turntable on which the bobbin holder shafts are arranged in aconcentric pattern and which rotates around the central axis of saidconcentric circle, characterized in that the bobbin holder shafts areconfigured from at least a first bobbin holder shaft which supports afirst bobbin, and a second bobbin holder shaft which supports a secondbobbin, wherein if the fiber bundle wound around the first bobbin hasbeen unwound and little remains, by rotating the turntable and splicingthe fiber bundle of the first bobbin and the fiber bundle of the secondbobbin, unwinding of the fiber bundle wound around the second bobbin isstarted.
 2. The fiber bundle supply device according to claim 1,characterized in comprising a first fiber bundle guide and a secondfiber bundle guide which are installed on the turntable and which rotatewith the turntable, wherein when the turntable starts rotation, thefirst fiber bundle guide guides the fiber bundle unwound from the firstbobbin to be restricted in a prescribed trajectory, and when therotation of the turntable is terminated, the second fiber bundle guidesuperposes the end portion of the fiber bundle wound around the secondbobbin on the fiber bundle unwound from the first bobbin.
 3. The fiberbundle supply device according to claim 1 characterized in comprising asplicing device which splices the fiber bundle of the first bobbin andthe fiber bundle of the second bobbin together, wherein the splicingdevice splices the overlapped portion of the fiber bundle of the firstbobbin and the fiber bundle of the second bobbin.
 4. The fiber bundlesupply device according to any one of claim 1, characterized incomprising a cutter device which cuts the fiber bundle unwound from thefirst bobbin, wherein the cutter device cuts the fiber bundle unwoundfrom the first bobbin such that necessary and sufficient bondingstrength is obtained when all of the overlapped portion of the fiberbundle is spliced.